1. Field of the Invention
The present invention relates to a method of non-destructive inspection of a mechanical part, such as for example a turbomachine component.
2. Description of the Related Art
The wear of certain turbomachine parts can be inspected by a penetrant sweating technique that is effective in detecting compact defects that open to the surface and that are not obstructed, such as cracks, pores, or folds.
That technique requires the use of colored or fluorescent liquids presenting low surface tension and commonly referred to as “penetrants”, that are capable of penetrating by capillarity into open defects in parts. After such penetrants have been applied to the parts, have become impregnated, and then excess penetrant remaining on the surface has been eliminated, defects are made to appear by applying a fine layer of powder to the parts, which powder is made up of capillary tubes suitable for sucking up the penetrants that have penetrated into discontinuities of the part.
The sweating technique is nevertheless found to be constraint in practice, in particular since it requires a suitably qualified operator to act in order to interpret the results.
Furthermore, it can be relatively dangerous and polluting in that it makes use of substances that are flammable, volatile, and harmful.
Methods are also known for optically inspecting a mechanical part (e.g. from document US 2007/0122026A1), which methods consist in automatically defining a path for an image sensor and lighting means to move over the surface of the part, the path being established from a survey of the surface of the part or from digital data defining the surface of the part, with movement of the image sensor along said path serving to acquire images of the entire surface of the part. Those images then need to be examined and analyzed in order to detect defects in the surface of the part, with such examination and analysis giving rise to problems that have not been solved in satisfactory manner to date.